Seems like I'm quite lucky. In GSC I caught some shiny mons. Here:
Gold- Shiny Mareep (my first shiny, yay), Shiny Rattata just before Goldenrod City.
Silver- Shiny Caterpie (the golden worm, the best looking shiny IMHO), Shiny Belsprout
Crystal- Shiny Goldeen, Shiny Iglibuff (Odd egg), Shiny Elekid (Second run, odd egg), Shiny Magby (duh).
Counting the evolved forms and the Shiny Gyrados I reared 21 shinies. Though I never managed to get a shiny starter and shiny legendary despite try after try!